I just went in and re-checked in my plugin to the repository with tortoisSVN, and branch/tagged it and re-committed it.
The original version is 1.0, the new version is 1.1.
I tagged the main plugin php file as the new version, added the new stable tag to the readme file as well.
I have two versions in my tags folder. A 1.0, and a 1.1.
I have 1.0 installed on my site, and keep checking to see if it alerts me to update the plugin, but it doesn't. Why is this happening? I've taken all the appropriate steps. What could I be doing wrong?